[medium] Use coveralls.io to generate test coverage stats

[jseutter]

Some pull requests come in without tests, like pull #54, which are easily broken later. Test coverage stats would be a huge help to identifying which parts of the code are lacking tests, so this situation can be rectified.

http://wiki.python.org/moin/CodeCoverage is a good place to start looking. I believe Coverage and Figleaf were both good libraries and Figleaf builds on top of Coverage.

Things needed:

• When a special command is used, the tests are run and stats are gathered.
• A coverage report, can be html or plaintext, can be generated from the stats
• A list of packages that this functionality depends on
• Update the README file with this information

[iffy]

I've not used it but I've seen people use https://coveralls.io/

Also, the travis builds could make some kind of assertion about coverage. Newer versions of coverage.py let you fail if coverage doesn't meet some threshold.

[greedo]

+1 for https://coveralls.io/

Very easy to setup too!